Have you ever worked in PEI? I've never heard of this. I'm a teacher and it doesn't apply to me, but I have many friends and family who have other jobs and they rarely get 2 days off in a row. When I worked in a call centre, it was very rare for me to get 2 days off, and usually then only when I asked for it.
I've never worked in PEI. I have family there though, and you made me curious, so I looked it up. According to the Employment Standards Act of PEI:
16. (1) An employer shall provide each employee, except those employees excluded by the regulations, with an unpaid rest period of at least twenty-four consecutive hours in every period of seven days and, whenever possible, that rest period shall include Sunday.
So, you're right, in PEI, the 48 hours thing doesn't apply. You can legally be made to work 6 days a week, every week. In fact, even if you work 8 hours a day, for 6 days, you don't even get overtime. That doesn't start until you work more than 48 hours in a week. PEI workers get the short end of the stick, don't they?
Also, I decided to recheck the laws for Newfoundland, since I was going off of what I've been told, I've never checked myself. Turns out NL law is the same as PEI in that employers are only required to give 24 hours off in any 7 day period. But, overtime here starts at 40 hours, so most (full-time) employers won't do a 6 day work week.